One field of use of such a contact and electrical connector is to electrically connect electrical conductors on an outer side of a cylinder head wall of a combustion engine with electrical conductors on an inner side of the cylinder head wall of the combustion engine. Examples of such a use include terminating electrical components on the inner side of the cylinder head wall for engine brake management or terminating electromagnetic fuel valves for fuel injection management. In this environment, the contacts and the electrical connectors are exposed to vibrations, high temperatures, and external forces, particularly on the outer side of the cylinder head wall. Additionally, adequate sealing is needed to prevent pressurised engine oil on the inner side of the cylinder head wall from passing through to the outer side of the cylinder head wall and for preventing water on the outer side of the cylinder head wall from passing through to the inner side of the cylinder head wall.
An example of such a conventional electrical connector is disclosed in DE-A-196 30 333. The electrical connector has a housing with a plurality of contact receiving passageways that receive contacts. Each of the contacts has a body portion including a conductor engaging end for forming an electrical connection with a corresponding conductor and a terminal end for engaging a mating contact of a mating connector. First and second recesses are formed along each of the body portions for receiving first and second seal members. The first and second seal members are, for example, O-rings, and form a seal between the contact and the contact receiving passageway for preventing liquid from passing through the contact receiving passageway.
To use the conventional electrical connector as a lead-through through a cylinder head wall of a combustion engine, the housing of the electrical connector is mounted in a passageway of the cylinder head wall such that the mating connector is on the inner side of the cylinder head wall. In view of the limited space available at the cylinder head wall, the number of contacts that the electrical connector can accommodate is correspondingly limited. For example, if the housing is mounted in a passageway having a diameter of 30 millimeters (mm), then the electrical connector can only accommodate eight contacts. As the number of parameters handled by the motor management of combustion engines and the number of electrical sensors and/or actuators located on the inner side of the cylinder head wall increases, however, it is desirable to also increase the number of contacts that can be accommodated in the housing fitting in the 30 mm passageway.
Additionally, the location of the plug connection of the two mating connectors is at the cylinder head wall. Because the cylinder head wall is exposed to particularly strong vibrations, the plug connections are affected by the vibrations, particularly, the contacts having smaller dimensions. Moreover, vibrations and forces exerted on the conductors may cause the contacts to tilt as a result of the resilience of the first and second seal members. If the contacts tilt, the first and second seal members may become deformed. If the first and second seal members become deformed, the seal between the contact and the contact receiving passageway may deteriorate. Because the risk of such deterioration increases with a decrease in the dimensions of the first and second seal members, the ability to reduce the dimensions of the contacts is further limited.
It is therefore desirable to provide an electrical connector that can house more than eight contacts in a passageway having a diameter of 30 mm without adversely affecting the performance of the electrical connector.